Arthritis Knee Noise: Crepitus and Popping Explained

Is your knee popping a sign of arthritis, or is it caused by something else?

Popping Knees and Crackling
Knuckles

Occasionally hearing pops, snaps, and crackles when you
bend your knees doesn’t necessarily mean you have arthritis. (Other joints
might make these noises now and then too.) However, it is common in those with
the condition.

Doctors call this sound “crepitus” (KREP-ih-dus). It generally
applies to the joints, but can be used to describe lung sounds as well.

Read on to learn what
causes crepitus and how to treat it.

A Look at
the Knee

The knee works like a large hinge. It joins the thighbone
(femur) to the long bone of the lower leg (tibia). The fibula, a bone in the
lower leg, is also connected to the joint. The kneecap (patella) is the small,
convex bone that sits at the front of the knee, shielding the joint.

Two thick pads of cartilage called the menisci cushion the
tibia and fibia, and reduce friction where they meet. A fluid-filled capsule
called the synovium encloses and lubricates the joint. Four ligaments—tough,
flexible bands that stretch across the uneven surface of the joint—connect the
bones.

Where Does Crepitus
Come From?

Over time, gas can build up in the areas surrounding the
joint, forming tiny bubbles in the synovial fluid. When you bend your knee,
some of the bubbles burst, and ligaments may snap or pop. This is normal, and
happens to everyone from time to time.

Arthritis, on the other hand, damages cartilage and bone.
As the damaged knee joint moves, it may crackle and crunch.

Crepitus also may be a result of an injury.

When to Be
Concerned About Crepitus

Crepitus in the knee is common and usually painless. There’s
no need to be concerned. But, pain that accompanies the crackling and popping
sounds could indicate a problem.

Knee crepitus is one of the common symptoms of
osteoarthritis (OA). It also can be one of the symptoms of rheumatoid or infectious
arthritis, and may accompany several different types of knee injuries.

See your doctor as soon as possible if your knee creaks,
crackles and hurts.

Crepitus
and Arthritis

Twenty-seven million Americans have OA. This type of
arthritis mainly affects those who are middle-aged and older. Also known as “wear
and tear” arthritis, OA commonly affects the joints used most often, such as
the joints in the hands. It also affects weight-bearing joints like the knees
and hips.

Mechanical stress or biochemical changes slowly break down
the cartilage that cushions the joint, causing inflammation and pain. Over
time, the cartilage is destroyed and the bones grind together. When crepitus is
accompanied by pain, it’s usually caused by OA.

Other Medical
Causes of Crepitus

Crepitus in the knees may be caused by knee injuries such
as meniscus (cartilage) tears. These
are fairly common in people who play sports, jog, and run. A meniscus tear can
cause crepitus as the joint moves.

Chondromalcia patella (patellofemoral
pain syndrome) is a
dull ache behind the kneecap (patella), usually caused by overuse or injury. You
can feel and hear a painful crunching and grating when the knee is moved. Other
knee injuries or types of arthritis can also cause crepitus.

Treating
Crepitus When It Hurts

Crepitus is harmless and needs no treatment when it isn’t
caused by disease, injury, another condition, and doesn’t hurt. But, when pain
accompanies a crunchy knee, treatment will depend on the underlying cause.

For instance, OA has a variety of treatments. Your doctor
may prescribe nonsteroidal anti-inflammatory drugs (NSAIDs) and suggest
applying ice packs to reduce inflammation. A brace can help support and rest
the knee. Physical therapy will strengthen the muscles that support the knee
and promote an increased range of motion.

In some cases, surgery or joint replacement may be
necessary.

Alternative
or Complimentary Treatments for Crepitus

Natural medicines and treatments for joint pain are
available at most drugstores and health food stores. Just keep in mind that few
have been proven clinically effective.

Glucosamine, especially in combination with chondroitin, is
a common treatment for arthritis. Fish oil, which is rich in omega-3 fatty
acids and other nutrients, may be useful as well. Both are available in tablet
or capsule form.

Certain herbal tinctures and teas may soothe arthritis
pain. Heat packs and ice packs are proven effective relief. Meditation is an
excellent way to ease pain and may promote healing.

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